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We found no surface water when we arrived at Harper’s Well (March 14th, 2012) . The water table was nine feet below the broken-off rim of the well casing. The water tested at a salinity of five parts/thousand, about equal to a teaspoon of salt in a quart of water or unpleasantly salty soup, not quite as salty as soy sauce. Despite the lack of surface water, we found dramatic evidence of the history and power of running water at that site.

Impromptu well-water sampler

Measuring salinity

When Anza arrived at Cienega San Sebastian, the expedition spread out and investigated many wells, springs, and pools looking for the ones with the freshest water. While the main camp was probably a half-mile north on San Felipe Creek, the arroyo at Harper’s Well was certainly explored.

At Yuha Well, Anza’s crew dug wells, undoubtedly starting in the creek bed of the arroyo. Later, permanent wells were dug starting up the stream banks so that the wells would not fill with sand when water flowed in the arroyo. Likely the first wells at Harper’s Well were dug in the creek bed. Harper’s Well became an important water source for later immigrants, and a permanent well with an iron casing was drilled up in the bank of the arroyo.

At Harper’s Well today, the arroyo has meandered, eroding away several feet of the bank. Twelve feet ten inches of well casing has been exposed and toppled, now lying on a sand bar. About 50 yards upstream, several segments of concrete wall lie toppled over on the stream bed.

This animation shows stream-bank erosion and sand bar deposition between 2005 and 2008 at Harper’s Well. Click for a larger version in a QuickTime format.

The animation begins with a 2005 image from Google Earth, locating the well and wall. When the arroyo does flow, the water runs from the south at the bottom of the picture towards the north at the top. The road appears as a dashed line, and then the low-flow stream channel is shown in magenta. Notice that at this point, the well is sticking up out of the low-flow channel.

The background image then changes to a 2008 image. Between 2005 and 2008, massive downpours must have taken place, because the meander bend downstream of the well has eroded its way about 35′ to the northwest, as can be seen when the 2008 low-flow channel appears in red. As typically happens, a sand bar has built up on the bank opposite the greatest erosion.

Finally the zone of greatest erosion is indicated in blue, and the area of sand bar deposition is indicated in green. Note that the sand bar has elevated the terrain immediately around the well casing, so the well is no longer in the low flow channel.

We have not yet uncovered actual historic records of the site, but from what we have seen, one can readily infer the story. This area is the exposed bed of an ancient lake, a location of very low gradients (160 feet below sea level) in a terrain of minimally lithified, lake-bottom sediments. Rainfall is scarce, but often occurs in extreme downpours. In such situations streams can meander rapidly.

Toppled wall lying in wash upstream of well

This sequence of meandering and erosion of some stream banks balanced by deposition of sand bars on opposite banks continues through decades, centuries, and millennia. It appears that in the past when erosion first threatened the well, the wall was built upstream to protect the stream bank and the well. However, as they ultimately will, the natural processes of downpours, flooding, and stream dynamics overwhelmed the efforts to protect the bank, the wellhead was lost and at some point, the well casing stood up at least 12 feet out of the stream bed before toppling due to rust and perhaps human intervention.

The heart of San Sebastian "Marsh." The larger trees are mesquite, smaller shrubs are creosote bush, salt cedar is invading the arroyos. Google Earth Image

In gratitude, Anza named the site for the Indian Sebastian Taraval, nicknamed Peregrino (the wanderer), who successfully led them here to water.

“To this site I gave the name of Zienega de San Sevastian, alias del Peregrino. In the place where we halted there is a good spring of very potable water, and there are many others to the west which are saline. From them is formed a marsh more than a league long with plentiful pasturage, although it is likewise salty.” –Juan Bautista de Anza, March 10, 1774; translated by Herbert Bolton, 1930; underlines ed.

One of the themes of our research is linguistic. Much of the Spanish-language vocabulary used by the explorers and colonists included words with obsolete spelling conventions and words that do not have good English-language equivalents. The English language is a product of Northern Europe where there are wet summers and an old, stable, mature terrain. Spanish is a product of the Mediterranean and Northern Africa, which, like California, is summer dry, and has a tectonically active, young, immature terrain. It is not surprising that the Spanish vocabulary for aquatic features is better attuned to many features of California and the desert southwest than is the English vocabulary. This is a good opportunity to take a moment to look at how our preconceptions of both language and terrain have influenced our reconstructions of history and historical ecology.

The Anza quote is a perfect example of the linguistic issues. The first issue is the simple issue: in modern Spanish, Zienega de San Sevastian becomes Ciénaga de San Sebastian. The second one is the real problem. Bolton, as others would have, translated Zienega as “marsh.” In our explorations of this fantastic ecosystem, a nagging question remained: where’s the marsh? Answer: Ciénaga does not translate into English; what we saw we would not call a vast marsh.

As currently defined in Wikipedia:

A cienega or cienaga (in modern Spanish ciénaga) is a Spanish Colonial term for a spring, that is in use in English in the southwestern United States. A cienega usually is a wet, marshy area at the foot of a mountain, in a canyon, or on the edge of a grassland where groundwater bubbles to the surface. Often, a cienega does not drain into a stream, but evaporates, forming a small playa.

That is exactly what we found, seeps and shallow groundwater in deeply incised washes. As most of the water does evaporate, accumulated salt (we found water at twice the salinity of ocean water) prevents the growth of the emergent aquatic plants that is central to the modern definition of a “marsh.”

Topographic Map of San Sebastian Marsh at the confluence of San Felipe and Carrizo Creeks. The author of this map was generous in his representation of the verdancy of the site. Click to enlarge.

Then there are the preconceptions of terrain. In other regions of the West, Imperial and Coachella Valleys might have been a land of mesas and canyons, but here the collision of tectonic plates crushes the terrain, liberating a flood of gravels engulfing upturned sedimentary layers and thrusting up isolated mountain peaks. As you drive across the desert towards Arizona on I-8, I-10, or CA-78, mountains appear to pop up out of a sea of gravelly piedmont sparsely scattered with creosote bush and pockmarked with occasional stands of mesquite. It takes attention to notice that the piedmont is not flat, but dips and rolls across its component alluvial fans, ultimately sloping to the Salton Sea, 230-feet below sea level. Unless you are driving through a monsoon cloudburst, overpasses span dry washes or if wet, irrigation canals.

For those of us from temperate climes, rivers are often recognized by the swath of riparian vegetation snaking its way across the surrounding terrain. Recent research demonstrated (using a model with alfalfa sprouts!) that the riparian vegetation is a requisite component of a stream system that forms a classic meandering pattern upon the landscape. Due to the extended drought periods and saline soils, the washes are devoid of extensive riparian vegetation. This and the abundant gravel supply result in the streams having braided channels.

Nothing calls out that there are rivers here. Those east-west highways are situated along the strips of high ground. The low relief of the piedmont masks that here, like elsewhere, the landscape is a mosaic of watersheds. The highways are largely following the watershed divides. But for Anza, who was travelling north-south and in desperate need of water, understanding the watersheds was key. The strips of high ground on which we zip by were treacherous barriers to the expeditions, for they were certain to have no water and poor pasturage.

San Felipe Watershed. Blue lines are the creeks/arroyos; the red line outlines the watershed. Google Earth Image. Click to enlarge.

So, what is here and what did Anza encounter? Moving north from the Yuha Basin the expeditions spent a night on Coyote Wash, then the rest of Anza’s desert journey was within the vast San Felipe watershed. It runs approximately 60-miles north-south from Toro Peak to Superstition Mountain, and covers about 1,500 square miles. It includes the Borrego, Carrizo, and Terwilliger Valleys. The heart of the system is known as San Sebastian Marsh where dozens of creeks come together before flowing on to the Salton Sea near Kane Springs.

Anza’s first camp after reentering California from Mexico was chosen for plentiful pasturage, knowing that there would be water the next night at Yuha Well.

Anza Campsite March 7, 1774

…we were told that a league away there were some wells of fresh water. Because there was plentiful pasturage at the place where we were, and not a great abundance of it at the watering place, we decided to pass the night here. –Juan Díaz, March 7, 1774

Cryptantha

This site is just south of Hwy. 98 near the turn off for Yuha Well. The area is dominated by the ubiquitous, but unpalatable, creosote bush. This being a very dry year, other vegetation at the site was largely limited to very stunted wildflowers and almost no grasses. The years of the Anza expeditions were wetter and vegetation must have surpassed 2012.

The Yuha Basin, Anza’s Second Camp

Yuha Basin is a major feature of the desert west of El Centro. Drained into the Salton Sea by Yuha Wash and then New River, this basin slowly enlarges at the expense of the surrounding Yuha Bluffs. Google Earth Image

Yuha Well was long used by travelers crossing the desert before the first Spanish explorations. Knowledge of it, shared by the Indians, was crucial to the success of the Anza expeditions.

Entering the basin is more ominous than promising.

At seven o’clock in the morning we took up the march over good country towards the northeast, and having gone about a league and a quarter we reached the wells mentioned, and when they were opened they poured forth an abundance of the finest water. We called them Santa Rosa de las Lajas. –Anza, March 8,1774.

Anza’s men dug out pits, probably in the floor of the wash, to obtain water for themselves and their livestock. Their enthusiasm for the water quality may have been heightened by how little potable water they had encountered since crossing the Colorado River.

To avoid being filled in every time water flowed down the wash, in later years, cased wells were dug up on the banks of the wash. But in time, these wells too filled in, probably by blowing sand.

For a dirt road in the desert, the route into Yuha Wells from Hwy 98 is very easy to follow. The starting point is unmistakable due to a very tall radio tower at the roadside. Updated signage, along with a map and audio tour available from BLM, make the route clear. 2WD with clearance would be adequate to get to the overlooks of the Yuha Basin. Getting down into the basin is best with 4WD, but a pickup with a granny gear, or the venerable VW dune buggy would do just fine.

Pickleweed & Saltgrass

Like elsewhere in the desert, rainfall was very scarce this year and no moisture was evident anywhere. The presence of the salt-marsh plants pickleweed and saltgrass, suggests that these days, even in wet years, drinkable water would be hard to find.

While we were there, a crew from American Conservation Experience arrived and started working a couple hundred yards up the wash. They have a contract with BLM to reduce and remediate visitor impact in this fragile desert ecosystem.

On February 13th the quest to catalog the aquatic habitats encountered by the Anza expeditions in California began. Research on the trail disclosed that portions, in fact some of the more interesting portions, are not accessible to our truck. Horseback is, however, an option. Riding a horse in the desert, it seems like one needs boots, and I didn’t have any that seemed right. After my usual fussing around I finally located a pair I wanted at a working-man’s store in Hayward. Their perfect fit and my happy toes were celebrated by driving directly to the nearest Anza camp site.

San Lorenzo Creek (Arroyo de Harina)

This site is where the monument to Anza’s camp had been located. The plaque is currently missing due to renovation of Anza Park, but that’s not the only problem. Anza’s expedition was traveling on horseback and heavily laden mules. Imagine getting horses and heavily laden mules down and back up that stream bank. We have the journals of Anza and the expedition’s padre Father Font, but like many of the campsites, the expedition left no physical evidence of their passing and the journals are not sufficiently specific to give the exact location, therefore some inference is necessary.

This image is high-resolution LiDAR topography of Hayward from USGS projected on Google Earth. The view is looking east (upstream) towards Castro Valley. The thin red line is the trace of the Hayward Fault.

The earliest routes originally trodden by Indians and later by the arriving explorers, missionaries, and rancheros were typically far enough up from San Francisco Bay to avoid salt marshes and other miry lowlands, but far enough down the piedmont so as to avoid foothills and deeply incised stream channels. Mission Blvd. is one such route. Of course, there was no bridge over the creek as appears in the LiDAR image, but the creek channel would have been much easier to cross there than upstream at Foothill Blvd.

From: Creek & Watershed Map of Hayward & San Leandro, Janet M. Sowers & Christopher M. Richard. The creek where indicated in blue is the natural creek bed. Red lines are where the creek is in a concrete flood-control channel. Red dots are where the creek is in a culvert.

The creek at the likely campsite is in an inaccessible concrete culvert, which raises a problem – the relevance of an ecological characterization of what Anza saw. Consequently, the ecological workup will characterize the nearest remaining natural stretch, right back where the historical monument was placed.

Next week we depart for the California/Mexico border where we will begin following the Anza Trail in earnest. Stay tuned to this blog for dispatches from the field.